Biochemical reference intervals for captive bred Crocodylus moreletii and Crocodylus acutus in the Alcuzahue Lagoon, Colima, Mexico

Abstract

Crocodylus moreletii and Crocodylus acutus are two endangered crocodile species endemic to Mexico. In this descriptive cross-sectional study, a total of 58 crocodiles (30 females and 28 males) were examined to determine and evaluate 24 blood biochemical indicators associated with energy, lipid, protein, mineral and enzymatic metabolic processes. Most of the serum biochemistry parameters were similar among sexes by species. However, male crocodiles showed higher triacylglycerol concentration and alkaline phosphatase activity, and lower globulin concentration than females. There were some significant differences between species. Total bilirubin, triacylglycerol, carbon dioxide, and hydrogen carbonate were higher in Crocodylus moreletii, and urea nitrogen, creatinine, alanine aminotransferase, and aspartate aminotransferase were higher in Crocodylus acutus. These reference values are very important for the protection of crocodiles. The calculated confidence intervals could be used to detect alert situations when at least 5% of the sampled crocodiles would fall outside of the calculated reference interval for a given parameter.